onlyborn

1. not comparableBorn as the only child in a family, flock, or the like.

   An onlyborn parent who is level has plenty of good qualities: He tends to be self-reliant.

   1986, G. Hugh Allred, Teenager: A Survival Guide for Mom and Dad, Bookcraft, →ISBN, page 137

plural onlyborns

1. The only child to be born to a parent or family.

   One of the most extensive studies ever undertaken tracked more than three thousand high school students — half were onlyborns, half had one sibling — for a twenty-year period.

   2001, Susan Newman, Parenting an Only Child: The Joys and Challenges of Raising Your One and Only, Broadway Books, →ISBN, page 49

   Synonyms: only child